Abstract: A method for arranging receiving unit sets and improving the interference resistance thereof is provided. An arranging method includes: a step of arranging a first receiving unit set including one or more first receiving units that receive a positioning signal transmitted from a terminal device, at a first position; a step of arranging a second receiving unit set including one or more second receiving units that receive the positioning signal, at a second position; and a step of arranging shielding members for changing a propagation distance of the positioning signal.

Abstract: An authentication-gaining apparatus includes: an acquiring unit that acquires unique information; an encrypting unit that encrypts the unique information using a cryptographic key, thereby generating encrypted information; and a transmitting unit that repeatedly transmits an authentication request containing the encrypted information, to an authentication apparatus, during an authentication period, wherein multiple authentication requests respectively containing encrypted information obtained by encrypting multiple pieces of unique information are transmitted during the authentication period.